Within the manufacturing process of semiconductors, presence of the foreign matters on a semiconductor substrate (i.e., a wafer) comes to be a cause of generation of defects, such as, insulation failure (or, ill insulation) or short-circuiting between wiring patterns, etc. Further, accompanying with miniaturization of the semiconductor elements, such the foreign matters, but being fine or microscopic much more, also comes to be the reason of ill insulation of a capacitor and/or breakage of gate oxidization films, etc. Thus, such the foreign matters, including those generated from movable portions of a conveyer, those generated from a human body, those produced by processing gas through reaction thereof within a processing apparatus, and those mixed within chemicals and materials, for example; they are mixed up with one another, under various conditions and due to various kinds of reasons thereof.
In the similar manner, within the manufacturing process of a liquid crystal display device, the device results into the useless if generating any kind of defects therein, such as, mixture of foreign matters in the patterns thereon, for example. Also, being similar in the condition mentioned above, within the manufacturing process of a printed circuit board, mixture of the foreign matters also results into short-circuiting and/or ill connection of patterns thereon.
As one of such technologies relating to the conventional arts, for detecting the foreign matters on the semiconductor substrate, for example, in Japanese Patent Laying-Open No. Sho 62-89336 (1987) <Conventional Art 1>, there is disclosed a technology of detecting lights scattered from foreign matters while irradiating a laser beam thereupon, being generated in a case when the foreign matters adhere upon the semiconductor substrate, and then making comparison thereof, with using the results of inspection obtained previously, upon the same king of semiconductor substrate, so as to neglect a false report due to the patterns thereon; thereby, enabling an inspection of foreign matters and defects with high sensitivity and high reliability. Also, as is disclosed in Japanese Patent Laying-Open No. Sho 63-135848 (1988) <Conventional Art 2>, for example, there is also known a technology of detecting lights scattered from foreign matters while irradiating a laser beam thereupon, being generated in a case when the foreign matters adhere upon the surface of semiconductor substrate, and then analysis is made upon the foreign matter detected, through the analyzing technology, such as, the laser photoluminescence or the secondary X-ray analysis (XMR), etc.
Also, as a technology for inspecting the above-mentioned foreign matters, there is disclosed a method of removing the lights emitted from repetitive patterns upon a wafer when irradiating coherent lights upon the wafer through a space filter(s), thereby detecting the foreign matters and/or defects having no such repetitiveness, with emphasis thereof. Further, a foreign matter inspecting apparatus is also already known, for example, in Japanese Patent Laying-Open No. Hei 1-117024 (1989) <Conventional Art 3>, in which apparatus a light is irradiated upon circuit patterns formed on a wafer from a direction inclined by 45 degree with respect to a group of main lines of the said circuit patterns, thereby preventing the 0th-order diffracted light from entering into an opening of an objection lens. Moreover, as the conventional technologies relating to a defects inspecting apparatus and a method thereof, for inspecting foreign matters, etc., there are also already known the followings: Japanese Patent Laying-Open No. Hei 1-250847 (1989) <Conventional Art 4>; Japanese Patent Laying-Open No. Hei 6-258239 (1994) <Conventional Art 5>; Japanese Patent Laying-Open No. Hei 6-324003 (1994) <Conventional Art 6>; Japanese Patent Laying-Open No. Hei 8-210989 (1996) <Conventional Art 7>; Japanese Patent Laying-Open No. Hei 8-271437 (1996) <Conventional Art 8>; and Japanese Patent Laying-Open No. 2000-105203 (2000) <Conventional Art 9>. In particular, the conventional technology 9 describes that a size of detecting pixel can be changed through exchanging a detection optic system. Also a technology for measuring a size of foreign matter is disclosed in Japanese Patent Laying-Open No. 2001-60607 (2001) <Conventional Art 10> and Japanese Patent Laying-Open No. 2001-264264 (2001) <Conventional Art 11>, for example.